KR20010087543A - A digital radiation image processing apparatus - Google Patents

Abstract

PURPOSE: An apparatus for processing a digital radiation image is provided to remarkably reduce the exposed degree of a radiation of a user by using a relatively small radiation. CONSTITUTION: A slit(211) prevents the scattering of a radiation by guiding a constant amount of radiation into a predetermined space formed on the upper portion of a shielding film. A protective cover(212) is made of a transparent material so that the radiation transmitted through the slit(211) penetrates the protective cover(212). A phosphor(213) converts the radiation into a visible light by responding to the radiation transmitted through the protective cover(212). A photo conductor(214) converts the visible light generated from the phosphor(213) into a corresponding electric signal. The photo conductor(214) is utilized as a solid state photoelectric conversion device. A photo diode could be used in lieu of the photo conductor(214).

Description

A digital radiation image processing apparatus

The present invention relates to a digital radiation image processing apparatus, and more particularly, to a digital radiation image processing apparatus for outputting a high resolution image by coating a phosphor (phosphor or scintillator) on the surface of the linear sensor.

Currently, radiological imaging is adding to its utility for medical and industrial applications. In the field of medical diagnostics, images of the human body are recorded on photographic films sensitive to X-rays. Screens containing phosphors that are sensitive to X-rays are installed between the human body and the film so that the X-ray dose rate is reduced. Combining the film for X-rays and the phosphor-enveloping screen provides a radiograph with good resolution. However, the above film requires a considerable development time, and the image of such a film has an inconvenience that its shape does not suit computer memory or analysis. Thus, technologies using X-ray intensifiers, video cameras, displays and non-film detectors are emerging.

The system uses a scintillation crystal that allows the X-rays to be converted into the corresponding visible light. The photo detector is used to generate an electrical signal corresponding to the intensity of visible light. The electrical signal from the photo detector is converted into digital data and stored in a memory device or electrically displayed on a cathode ray tube.

Solid state detectors have also been used in X-ray astronomy. The system includes an array of photodiode matrices that are charged by light, so that electron-hole pairs are provided. The photosensitive device comprises back-to-back diodes, i.e., photo-responsive diodes on one side and blocking diodes on the other. Each diode has an associated capacitance formed by its electrode. The magnitude of the charge present on a given capacitor is sensed and correlated again to the intensity of incident radiation impinging on the photosensitive diode. In addition, in such a linear photodiode array, the scanning time is too long to make a real-time reading.

An example of the prior art disclosed in Korean Patent Application No. 1991-2182 proposed to solve this inconvenience is a radiation detection apparatus having a pixel array as shown in FIG. 1. Its construction consists of a light emitting layer (scintillator) with an X-ray sensitive phosphor, an amorphous silicon Schottky barrier diode array layer (2), and a polycrystalline silicon thin film transistor array layer. (poly silicon thin film transistor array layer) 3 and a readout circuit 4.

The phosphor in the light emitting layer 1 converts incident X-rays into corresponding visible light. The amorphous silicon Schottky barrier diode array 2 generates an electrical signal corresponding to the intensity of the light provided from the light emitting layer 1. The current generated in the photodiode array 3 is provided to the gate of the associated TFT. Each pixel includes a photodiode. The photodiode is connected to a gate of a thin film transistor. Photodiodes generate current when the radiation detection device receives X-rays.

The readout circuit 4 amplifies the electrical signal, converts the analog signal into a digital signal, and stores the digitally converted signal in a memory so that the stored signal can be used in an optical or electrical display. The detector can be formed on a single module or multiple modules (tiled structure) and has a readout circuit 4 incorporated on the same substrate. The readout circuitry is based on high mobility poly silicon technology, which is well known in the art, and is installed along a single module or around a multi-module structure.

On the other hand, another example of the radiation detector according to the prior art is a technique disclosed in US Patent No. 4,922,103 is configured as shown in Figure 2a. Light emitter 6 for storing the radiation energy provided from the radiation output device 7 in a radiation image, and the radiation energy stored in the light emitter 6 formed on the surface of the light emitter 6 is converted into a photoelectric signal And a scan circuit 5B for converting the information detected by the line sensor 5 into digital data in association with the operation of the radiation output device 7. Although not shown, the line sensor 5 moves in the longitudinal direction of the light emitter 6 in conjunction with the operation of the radiation output device 7.

FIG. 2B is a partial front cross-sectional view of FIG. 2A in which radiation output from the radiation output device 7 is transmitted to the light emitter 6 through the slit 7A, and the visible light generated from the light emitter 6 includes a plurality of photosensitive sensors. Detected by 5A and delivered to scanning circuit 5B.

However, this technique still extracts the radiation energy temporarily stored in the scintillator 6 to the line sensor, so that the radiation output from the radiation output device 7 must pass through the human body to reach the light emitter. Therefore, there is still a problem in that the amount of radiation exposure to the human body should be reduced. In addition, there is a problem that the radiographic image temporarily stored in the luminous body is not accurately transmitted by the interference element such as interference of light.

An object of the present invention is to provide a digital image processing apparatus using an image sensor coated on a surface thereof.

Another object of the present invention is to provide a digital radiation image processing apparatus having a high resolution.

It is still another object of the present invention to provide a digital radiation image processing apparatus capable of reducing the exposure amount of radiation.

It is another object of the present invention to improve the resolution by reducing the scattering of light provided from the radiation output device.

The digital radiation image processing apparatus according to the present invention for achieving these objects is a surface having a stimulating ray source and a phosphor for converting the radiation energy provided from the radiation output device into visible light. A linear sensor which is coated on and displays an electrical signal corresponding to the intensity of visible light emitted from the phosphor, scanning drive means for driving the image sensor, and an output signal of the image sensor. It is characterized in that it comprises a read-out means for reading sequentially and converting into digital data.

A detailed feature of the digital radiation image processing apparatus according to the present invention is that the image sensor unit is configured using a linear sensor.

Another detailed feature of the digital radiation image processing apparatus according to the present invention is that the image sensor unit includes a plurality of linear sensors arranged so that predetermined portions overlap each other.

Another detailed feature of the digital radiation image processing apparatus according to the present invention is that the configuration of the image sensor unit is a protective cover made of a material which protects the optical sensor from external influences and can transmit radiation, and is coated on the lower end of the protective cover It includes a phosphor (scintillator or phosphor) for converting the visible light in response to the radiation transmitted through the protective cover, and an optical sensor for converting the visible light generated from the phosphor into an electrical signal.

Another detailed feature of the digital radiation image processing apparatus according to the present invention is that a shielding film having a slit formed on an upper predetermined surface is added to the image sensor to prevent scattering of radiation provided from the radiation output device. It is composed.

Another feature of the digital radiation image processing apparatus according to the present invention is that the radiation output apparatus and the image sensor unit are configured to be synchronized in the same direction.

Another feature of the digital radiation image processing apparatus according to the present invention is that the image sensor unit coated on the surface of the radiation output device and the phosphor is fixed, and the object to be photographed is located therebetween. It is a point provided with the conveying means to drive.

1 is a perspective view showing the configuration of a radiation detector according to the prior art,

Figure 2a is a perspective view showing the configuration of a radiation detector according to another prior art,

2B is a partial cross-sectional view of FIG. 2A;

3 is a perspective view showing the configuration of a digital radiation image processing apparatus according to an embodiment of the present invention;

4 is a cross-sectional view of the linear sensor shown in FIG. 3;

5 is an exemplary operation diagram of a digital radiation image processing apparatus according to another embodiment of the present invention;

6 is a perspective view showing the configuration of a digital radiation image processing apparatus according to another embodiment of the present invention.

Hereinafter, a configuration and operation thereof of a digital radiation image processing apparatus according to the present invention will be described with reference to the accompanying drawings.

3 is a perspective view showing the configuration of a digital radiation image processing apparatus according to an embodiment of the present invention. As shown, a stimulating ray source 100 and a phosphor that converts radiation energy provided from the radiation output device 100 into visible light are coated on the surface of the phosphor. An image sensing portion 200 for generating an electrical signal corresponding to the intensity of the visible light generated from the light source, scanning drive means 300 for driving the image sensor 200, It is shown that the detection means (read-out means) 400 for sequentially reading the output signal of the image sensor unit 200 to convert to digital data.

Unlike the prior art of FIGS. 2A to 2B, the image sensor unit 200 according to the present invention is composed of a plurality of sensor blocks having a structure in which a plurality of linear sensors 210 overlap each other. In other words, the conventional technology uses an image sensor having a length corresponding to the width of the sinchiller, and thus, the product is expensive, but a relatively inexpensive linear sensor is configured so that portions overlap each other.

In addition, in the example of FIG. 2A, the image sensor unit is formed using a plurality of linear sensors. However, in some cases, that is, when the radiation exposure range is small, one image sensor may be configured using one linear sensor.

4 is a preferred cross-sectional view of the linear sensor 210 shown in FIG. As shown, a slit (211) for preventing a scattering of radiation by allowing a predetermined amount of radiation to be incident as a predetermined space formed on the shielding film, and a transparent material to transmit the radiation transmitted through the slit (211) A protective cover 212 and a phosphor (phosphor or scintillator) 213 for converting the visible light in response to the radiation transmitted through the protective cover 212 and the visible light generated from the phosphor 213 The photoconductor 214 converts the signal into an electrical signal.

By preventing the scattering of radiation by using a slit 211 formed by the shielding film, a grid used for scattering radiation in the prior art is unnecessary.

The photoconductor 214 is used as a solid state photoelectric conversion device. Alternatively, a photo diode may be used instead of the photo conductor. In the present example, the shielding film formed on the predetermined portion of the slit is included in the image sensor unit, but the protective cover, the phosphor, and the optical sensor may be implemented without the shielding film. In addition, unlike the example of FIG. 4, the image processing according to the present invention may be implemented by coating the phosphor on the upper surface of the protective cover and configuring the sensor on the lower surface of the protective cover. However, the protective cover at this time should use a transparent material so that visible light generated from the phosphor can be transmitted to the optical sensor.

5 is a diagram illustrating an operation of a radiographic image processing apparatus according to another exemplary embodiment of the present invention. Unlike the embodiment of FIG. 3, the radiation output device 100 and the image sensor 200 are simultaneously driven.

6 is a perspective view showing the configuration of a radiographic image processing apparatus according to another embodiment according to the present invention. In the example of FIGS. 3 to 5, the image sensor unit is driven or the radiation output device and the image sensor unit are simultaneously driven while the non-photographing target (human or object) is fixed. In this example, it can be seen that the object to be photographed 520 moves on the conveyor belt 510 while the image sensor unit 200 coated with the phosphor is fixed.

When the radiation provided from the radiation output device 100 passes through the object to be photographed and is transmitted to the image sensor unit 200, the corresponding image is converted into an electrical signal and displayed on the detection device 400. In this case, the image sensor unit 200 may be implemented in various forms as shown in FIGS. 3 to 4.

As described above, the present invention can minimize the scattering of the image by directly attaching a radiation sensing material (phosphor) on a linear sensor to extract a high-resolution image, the user uses a relatively small amount of radiation There is an effect that can significantly reduce the radiation exposure of the. In addition, it is possible to improve the resolution by reducing the scattering of the light provided from the radiation output device, it is possible to reduce the cost required for manufacturing by miniaturizing the scintillator.

Claims (9)

A stimulating ray source, An image sensing portion, which is coated on a surface with a phosphor that converts radiation energy provided from the radiation output device into visible light, indicates an electrical signal corresponding to the intensity of visible light generated from the phosphor. Wow, Scanning drive means for driving the image sensor unit, And read-out means for sequentially reading the output signal of the image sensor unit and converting the output signal into digital data. The method of claim 1; And the radiation output device and the image sensor unit move in the same direction in synchronization with each other. A stimulating ray source, An image sensing portion coated with a phosphor to convert radiation energy provided from the radiation output device into visible light and displaying an electrical signal corresponding to the intensity of visible light generated from the phosphor; , Moving means for moving the object to be photographed so as to be located between the radiation output device and the image sensor unit; And read-out means for sequentially reading the output signal of the image sensor unit and converting the output signal into digital data. The method of claim 1 or 3; The image sensor unit, Digital radiation image processing device, characterized in that consisting of a linear sensor. The method of claim 1 or 3; The image sensor unit, Digital radiation image processing apparatus, characterized in that the predetermined portion is composed of a plurality of linear sensors arranged to overlap each other. The method of claim 1 or 3; The image sensor unit, A protective cover made of a material which protects the optical sensor from external influences and can transmit radiation; A phosphor (scintillator or phosphor) coated on a lower end of the protective cover and converting into visible light in response to radiation transmitted through the protective cover; And an optical sensor for converting visible light generated from the phosphor into an electrical signal. The method of claim 6; The image sensor unit, And a shielding film having a slit formed on an upper predetermined surface in order to prevent scattering of radiation provided from the radiation output device. The method of claim 1 or 3; The image sensor unit, A phosphor (scintillator or phosphor) for converting the visible light in response to radiation provided from the radiation output device, A protective cover made of a transparent material which is configured at a lower end of the phosphor to protect the optical sensor from external influences and to transmit visible light generated from the phosphor; And an optical sensor for converting visible light provided from the phosphor into an electrical signal via the protective cover. The method of claim 8; The image sensor unit, And a shielding film having a slit formed on an upper predetermined surface in order to prevent scattering of radiation provided from the radiation output device.